What is Islamic ruling of a Muslim who does not keep his beard in the way of Sunnah and shave part of the face and leaves the Jaw and many other ways for fashion?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

The hair that grows on the cheek is part of the beard; this is the opinion of the majority of Muslim scholars.

As for more details in this subject, please read the Fatawa: 81533 and 81978.

Allah knows best.